Hey Czechman,
I am doing the same with my 55 2nd. It has the 58-62 block which is full flow and was easy to tap. It is in the machine shop now so I had him tap out the holes. It is being re-assembled as we speak.
I am thinking of either puting the oil filter bracket on the firewall or inner fender. I will be watching this thread. Hopefully, we will get some pictures of what others have done.
Thanks